PVMBG reported that at 0640 on 12 April an event at Sinabung generated an ash plume that rose 200 m and drifted WNW.
At 1655 pyroclastic flows generated ash plumes that drifted WSW.
At 0827 on 15 April an event generated an ash plume rose 1 km and drifted WNW.
The Alert Level remained at 4 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions of 7 km on the SSE sector, 6 km in the ESE sector, and 4 km in the NNE sector.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)